1. Field of the Disclosure
The present application relates generally to latching systems. More particularly, the present application relates to container latches for a container chassis.
2. Description of the Background of the Disclosure
In a conventional container chassis used for transporting a container, the container is secured to the container chassis by two latches spaced apart at each of the two front corners and two latches spaced apart at each of the two rear corners of the container chassis. These latches are manually operated by the driver or other personnel. The rear latches may have a twist lock that is inserted into the bottom of the corner castings of a container. The twist lock may be operated by a lever to move the twist lock between an unlatched position and a latched position. The front latches of a conventional chassis that is 40 to 53 feet in length may have locking pins that extend horizontally into openings of the corner castings of the container. The front of a conventional chassis that is 20 feet in length may utilize a twist lock and manual lever rather than the locking pins.
Such conventional latching devices are manually operated by the chassis driver or other personnel when a container is placed on a chassis. In turn, the conventional latching devices are manually unlocked before the container is removed from the chassis. The driver or other personnel may improperly or incompletely lock or unlock the latching devices, which may cause improper unloading of the container from the chassis or create the potential for shifting of or losing a container during road transport. Thus, there exists a need for an automatic latching system that does not require human intervention.
In the railway transportation industry, a container is typically secured to the four corners of a flatcar using a swing-type latch. Two swing-type latches spaced apart at each of the two front corners and two swing-type latches spaced apart at each of the two rear corners of the flatcar secure the container thereto. Similar to the twist lock latch of a container chassis, the swing-type latches of the flatcar enter openings along the bottom surface of each corner casting of the container. Unlike the twist lock latch, the swing-type latch is continuously biased into position by a spring. As the container is placed on the flatcar, the latch is pushed back against a spring until the latch clears the bottom surface of the corner casting. The latch is designed such that a significant force must be applied against the latch to remove the container from the flatcar. A container weight of approximately 700 lbs may be required to load the container onto the flatcar, and a force of approximately 2,000 lbs, for example, is used to remove the container from the flatcar.